The Mechanisms of Developing the Withdrawal Syndrome by Non-Chemical Dependence and its Correction in the Experiment

Bevzuyk D. А., Levicheva N. А.

State institution "Institute of Neurology, Psychiatry and Narcology NAMS of Ukraine"

46, Academician Pavlov St., Kharkiv 61068, Ukraine

Abstract

A non-chemical (behavioral) dependence in rats-males aged 5-6 months, weighing from 250 to 320 grams, with a congenital anxiety-phobic form of behavior was modeled. Rats with anxiety-phobic behavior were selected by using a multi-parametric test for evaluating anxiety-phobic states according to V. I. Rodina, test "open field" and methods of zoo-social conflict.
The self-stimulation of the positive emotional zones of the behind ventrolateral hypothalamus (BVLH) was used as a model of non-chemical dependence. It was recorded for an hour within 7 days of rats. Previous studies had shown that rats with congenital anxiety-phobic behavior had different initial levels of need for positive emotions. The first group was made up of rats with a high frequency of self-stimulation (high level need for positive emotions). The second group was made up of rats with an average level frequency of self-stimulation (moderate level of need for positive emotions).
Material and methods. The electrical activity of the neocortex, the hippocampus, the hypothalamus, and the reticular formation has been recorded by using the Neuron-spectrum + complex bipolarity. Rats were injected with Proproten S-100 at a dose of 20 μl in a state of cancellation of getting positive emotions sublingually. Proproten S-100 was injected 2 times a day for three days. Statistic data processing was used with help non-parametric Wilcoxon’s criterion in program Statistica 6.0 and spectral analysis.
Results and discussion. The obtained results showed that the neurophysiological basis of the formation of the withdrawal syndrome of getting positive emotions in rats with an initially high level of frequency self-stimulation (first group) was the overstrain of the reticulo-hypothalamic mechanisms of the brain on a background of hyper-excitation of the hippocampal neurons, and in rats with an initially average level frequency of self-stimulation (moderate level of need for positive emotions ( second group) overstrain of the limbic-neocortical emotional system of the brain.
One-day forced sublingual injection of the Proproten S-100 to rats with a high level of need for positive emotions (the first group) lead to suppression of manifestations of convulsive activity of the hippocampal neurons and the reduced overstain of reticulo-hypothalamic mechanisms of the brain due to substitution of beta rhythm by low-amplitude alpha-theta waves, that correlated with the state of emotional rest in these rats. It was recorded that an increase in electrographic correlated with the emotional rest: the alpha-theta of waves in the background of oppression of beta rhythm, indicating a decrease in overstrain in the structures of the limbic-neocortical system of the brain in rats with a moderate level of need for positive emotions (second group).
Conclusions. Three-day forced sublingual injection of the Proproten S-100 to rats in first group was accompanied by an increase in anxiety level, which correlated with the appearance of numerous paroxysms in the EEG on the background of beta-rhythm growth in the hypothalamus and reticular formation, and its decrease in the neocortex and hippocampus. In rats from the second group there was an oppression of electrographic manifestations of excitation in the structures of the emotional limbic-neocortical system of the brain, accompanied by a decrease in anxiety levels.